91485-86-8Relevant articles and documents
1H NMR analysis of the tolylene-2,4-diisocyanate-methanol reaction
Yang, Peng Fei,Han, Yong De,Li, Tian Duo,Li, Jun Ying
experimental part, p. 853 - 855 (2011/12/16)
Tolylene-2,4-diisocyanate (2,4-TDI) 1 reacts with methanol through two simultaneous paths in the polyurethane reaction, which involve two different intermediates - tolylene-4-carbamatic-2-isocyanate 2 and tolylene-2-carbamatic- 4-isocyanate 3, and the final product is tolylene-2,4-dicarbamate 4. The-CH 3 chemical shifts in benzene ring in compounds 1, 2, 3 and 4 can be easily tested and well distinguished, through which those four compounds are quantified and their kinetics are investigated. It shows that four rate constants for the tolylene-2,4-diisocyanate-methanol reaction in CCl4 at 50°C are k1 = 9.6 × 10-2 h-2 mol-2 min-1, k2 = 1.4 × 10-2 h-2 mol-2 min-1, k3 = 4.0 × 10-3 h-2 mol-2 min-1, k4 = 1.4 × 10-3 h-2 mol-2 min-1. (k1 is the reaction rate constant from compounds 1 to 2; k 2 is the reaction rate constant from compounds 1 to 3; k3 is the reaction rate constant from compounds 3 to 4; k4 is the reaction rate constant from compounds 2 to 4).
